TI-2021-08399 Aliases CVE-2021-26720 GHSA-jhxr-wvf5-hrp6

avahi-daemon-check-dns.sh in the Debian avahi package through 0.8-4 is executed as root…

LOW 34CWE-59Published 2021-02-17 · Updated 2024-08-03

Key facts

Attack vector: Local
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · High · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

avahi-daemon-check-dns.sh in the Debian avahi package through 0.8-4 is executed as root via /etc/network/if-up.d/avahi-daemon, and allows a local attacker to cause a denial of service or create arbitrary empty files via a symlink attack on files under /run/avahi-daemon. NOTE: this only affects the packaging for Debian GNU/Linux (used indirectly by SUSE), not the upstream Avahi product.

Why it matters now

EPSS 0.00395 33rd percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
—	—	all versions	—	No fix listed	CNA

— Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 3

CPE	Versions	Role	Vendor
cpe:2.3:a:avahi:avahi::::::::	up to 0.8-4	Vulnerable	avahi
cpe:2.3:o:debian:debian_linux:9.0:::::::*	9.0	Vulnerable	Debian
cpe:2.3:o:debian:debian_linux:10.0:::::::*	10.0	Vulnerable	Debian

cpe:2.3:a:avahi:avahi:*:*:*:*:*:*:*:* Versions up to 0.8-4 Vulnerable ·avahi
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2021-26720
2026-10-03 Alias added: GHSA-jhxr-wvf5-hrp6

References

Advisory 10

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences